There is a category for Religions with a subcategory of Religious Professionals which has a subcategory of Missionaries. There are subcategories for a number of categories in various nations but not
Cuba. So it looks to me that you should create a subcategory of Missionary in Cuba an put her there. Though there is a subcategory under missionaries of Missionaries in Latin America which you might consider as well. It probably wouldn't hurt for you to post another question here to see what others would suggest.